Apparatus for producing nanofiber utilizing electospinning and nozzle pack for the apparatus

ABSTRACT

The apparatus for producing a nanofiber includes a supply unit ( 110 ) for supplying melted polymer for fiber material, a spinning unit ( 122 ) having several radiation nozzles ( 122 ) to which first voltage having a polar is applied to discharge the polymer solution supplied from the supply unit in a filament form, a collector ( 130 ) spaced apart form the spinning nozzles in order to pile the filament from the spinning unit and applied to second voltage having opposite polar to the first voltage, and a control unit ( 140 ) applied to the first voltage having the same polar as the charged filament and extended from an end of the spinning nozzle toward the collector at least at both sides of the spinning unit in order to prevent repulsion and dispersion of the filament stream radiated from each spinning nozzle.

TECHNICAL FIELD

The present invention relates to an apparatus for producing nanofiberand a nozzle pack for the apparatus, and more particularly to anapparatus for producing nanofiber utilizing electrospinning and a nozzlepack for the apparatus.

BACKGROUND ART

In general, the electrospinning is used to produce fibers having adiameter of several nanometers by using various kinds of polymers, i.e.,polymer melt, polymer solution, etc.

A nanofiber gives various physical properties, since the fiber shows avery high area-to-volumn ratio in comparison with the conventionalfiber. A web composed of these nanofibers is a material of porousmembrane, which is useful in various fields such as various filters, adressing for medical treatment and an artificial support.

In the conventional electrospinning, a fiber is manufactured bydischarging solution less than several grams per second from one or asmall number of nozzles, which is not economical due to the slowproducing rate.

U.S. Pat No. 4,323,525 discloses a technique related to theelectrospinning, in which a tubular product is made by electrostaticallyspinning a fiber-forming solution on a rotating mandrel charged at −50kV by three grounded syringes. However, this technique is not suitablefor manufacturing many nanofibers because of the restriction of a shapeand number of the spinning nozzles being adapted. In addition, since thetechnique is limited to manufacturing tubular products, it is difficultto continuously manufacture multi-purpose planar webs.

Until now, various electrospinning nozzles have been suggested in thefollowing documents: a syringe needle [J. M. Deitzel, J. D. Kleinmeyer,D. Harris, N. C. Beck Tan, Polymer 42, 261-272 (2001)]/[J. M. Deitzel,J. D. Kleinmeyer, J. K. Hirvonen, N. C. Beck Tan, Polymer 42,8163-8170(2001)], a capillary metal tube [Y. M. Shin, M. M. Hohman, M.P. Brenner, G. C. Rutledge, Polymer 42, 9955-9967(2001)], a capillaryglass [J. Doshi, D. H. Reneker, Journal of Electrostatics 35,151-160(1995)], etc.

As described above, the problem caused by a small number of the spinningnozzles can be overcame by using many nozzles. However, using manynozzles causes the discharge of solvent to be not easy and makes thestream of solution be irregular due to the repulsion between chargedfilaments.

On the other hand, Korean Laid-open Pat. Publication No.2002-0051066discloses “Apparatus for producing a polymer web”, which includes a basehaving an inlet pipe for allowing melted polymer materials to passthrough, a base conductor board attached on the lower surface of thebase for transferring electric charges, at lease one nozzle mounted tonozzle taps formed on the base conductor board for discharging thepolymer material, a charge distribution board mounted to a lower portionof the base conductor board, and a conductor board mounted to a lowerportion of the charge distribution board.

Since all conductor boards for transferring electric charges are exposedand a separate conductor board is located between the base conductorboard and the collector, this apparatus disadvantageously forms toostrong and unnecessary electric fields between the spinning part and thecollector, causing the discharge of solution not regular when manyspinning nozzles are configured.

In addition, the strong electric field causes formation of agglomerationat ends of some spinning nozzles when the solution is discharged,thereby resulting that webs unclear or having irregular diameters aremanufactured.

On the other hand, if the apparatus is composed of multiple nozzles, thestream of solution deviates from its path due to the repulsion betweenthe filaments discharged with the same polarity, so the stream may notbe appropriately induced to a correct location on the collector.

DISCLOSURE OF INVENTION

The present invention is designed to overcome such problems of the priorart. Therefore, an object of the invention is to provide an improvedapparatus for producing nanofibers utilizing the electrospinning, whichmay prevent charged filament stream from deviating from its path whenbeing discharged

Another object of the present invention is to provide a spinning nozzlepack capable of stably discharging the charged solution.

In order to accomplish the above object, the present invention providesan apparatus for producing nanofiber utilizing electrospinning, whichincludes a supply unit for supplying polymer materials of the liquidstate used to produce fibers, a spinning unit having a plurality ofspinning nozzles for discharging the polymer materials supplied by thesupply unit in a charged filament form, a collector installed below thespinning unit for piling the charged filament discharged by the spinningunit in a specific thickness, and a control unit being charged to have avoltage of same polarity as one of the charged filament and locatedbetween the spinning unit and the collector for guiding the stream ofthe charged filament in order to prevent repulsion and dispersion of thecharged filaments discharged from each spinning nozzle.

In addition, the apparatus may further include an induction unitpositioned between the control unit and the collector to surround thefilament stream and charged at a voltage of same polarity as the controlunit for inducing the charged filament stream passing through thecontrol unit toward the collector.

In another aspect of the present invention, there is provided a spinningnozzle pack including a body having a supplier for supplying thesolution and a receiver for receiving the supplied solution, an electricconnector mounted on the body to be sunk in the solution for chargingthe solution when voltage is supplied thereto, and a plurality ofspinning nozzles having capillary tube for discharging the solutioncharged by the electric connector in a fine filament form.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of preferredembodiments of the present invention will be more fully described in thefollowing detailed description, taken accompanying drawings. In thedrawings:

FIG. 1 is a perspective view showing an apparatus for producingnanofibers utilizing the electrospinning according to one preferredembodiment of the present invention;

FIG. 2 is a sectional view showing the apparatus of FIG. 1;

FIG. 3 is an exploded perspective view showing a spinning nozzle packshown in FIG. 1 and FIG. 2;

FIG. 4 is a front view showing a modification of an electric connectorof the spinning nozzle pack shown in FIG. 3;

FIG. 5 is a perspective view showing the shape of the spinning nozzleshown in FIG. 3;

FIG. 6 is a perspective view showing a modification of the spinningnozzle of FIG. 5;

FIG. 7 through FIG. 9 show spinning nozzle packs according to severalembodiments of the present invention;

FIG. 10 is a schematic view showing an apparatus for producingnanofibers according to another preferred embodiment of the presentinvention; and

FIG. 11 is a schematic view showing an apparatus for producingnanofibers according to still another preferred embodiment of thepresent invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 and FIG. 2 are perspective view and sectional view respectivelyshowing an apparatus for producing nanofibers utilizing theelectrospinning according to one preferred embodiment of the presentinvention.

Referring to FIG. 1 and FIG. 2, the apparatus for producing nanofibers100 according to one preferred embodiment of the present inventionincludes a supply unit 110 for supplying melted polymer materials usedfor making fiber, a spinning unit 120 having a plurality of spinningnozzles 122 for discharging the polymer materials supplied by the supplyunit 110 in a charged filament form, a collector 130 spaced apart fromthe spinning nozzles 122 so as to pile the charged filament dischargedby the spinning unit 120 in a specific thickness, control units 140installed at least at both sides of the spinning unit 120, an inductionunit 150 positioned between the control unit 140 and the collector 130to surround the filament stream (S), and an air conditioning unit 160for injecting air into the space between the spinning unit 120 and thecollector 130 and evaporating solvent in this space so that the solventis ejected outside.

As shown in FIG. 1 and FIG. 2, the supply unit 110 includes a storagecontainer 112 for storing the solution in which polymer material usedfor making fibers are dissolved, a pump 114 for pressing the solutionstored in the storage container 112 so as to be supplied to the spinningunit 120 by a fixed quantity, and a distributor 116 for distributing thesolution to each nozzle.

The storage container 112 contains polymer solution or melted polymermaterial. In this case, the polymer material may adopt all kinds ofpolymer materials soluble in the solvent such as poly vinylidenefluoride (PVDF), polyacrylonitile (PAN), polysulfone (PS), polyimide(PI) and polyethylene oxide (PEO). On the other hand, a variety ofpolymer materials may be mixed in one storage container or each polymermaterial may independently stored in each storage container 112. Hence,it is possible to use many storage containers 112, if necessary.

The pump 114 may control a spinning speed of the spinning unit 120 bycontrolling its output.

The distributor 116 is installed between the supply unit 110 and thespinning unit 120, and distributes the solution transferred from thepump 114 to each spinning nozzle 122 via a transfer line 118 by a fixedquantity.

On the other hand, the present invention is not restricted in theabove-mentioned structure, but may be modified so that may supply units110 are independently linked to each spinning nozzle in order to supplysolution by more fixed quantity, of course.

The spinning unit 120 includes a plurality of spinning nozzles 122applied to a specific positive (+) voltage or grounded. The spinningunit 120 is preferably reciprocated at a specific speed in a directionof the arrow “A” in FIG. 1 above the collector 130 by means of thetransfer mount 124. The spinning unit 120 is used for spinning thecharged fiber-forming solution supplied from the supply unit 110 towardthe collector 130 in a shape of fine filament.

The positive (+) voltage is excited by output voltage of a high-voltageunit 170. The high-voltage unit 170 outputs direct current voltage inthe range of 10 kV˜120 kV.

The spinning unit 120 includes at least one spinning nozzle pack 126 inwhich a plurality of spinning nozzles 122 are arranged in series. Thenumber of the spinning nozzles 122 composing the spinning packs 126 orthe number of the spinning nozzle packs 126 composing the spinning unit120 is determined by synthetically considering size, thickness andproduction speed of webs to be produced. For example, it is desirablethat each spinning nozzle pack 126 has more than 10 spinning nozzles 122in case of manufacturing webs having thickness of 10˜100 μm and width of5˜100 cm at a speed of 1 m per minute, it is desirable that more than 10spinning nozzles 122 are configured in each spinning nozzle pack 126,and 1˜50 rows of the spinning nozzle packs 126 are arranged on thetransfer mount 124. More preferably, the number of the spinning nozzlepack 126 is in the range of 1˜20. FIG. 1 shows that ten spinning nozzlepacks are arranged at predetermined intervals, as an example.

In addition, when considering prevention of electric field interference,prevention of contact between discharging streams, and an availablespace of the spinning nozzles, it is desirable to arrange the spinningnozzles 122 mounted in the spinning nozzle pack 126 at intervals of 2˜50mm, more preferably 3˜30 mm. Here, an interval between the spinningpacks 126 is preferably in the range of 3˜30 mm, more preferably 20˜150mm.

FIG. 3 is an exploded perspective view of the spinning nozzle pack 126shown in FIG. 1 and FIG. 2.

Referring to FIG. 3, the spinning nozzle pack 126 includes a cover 10having a supplier 12 to which the solution used as fiber material issupplied, a body 20 having a receiving portion 22 capable of receivingthe supplied solution, an electric connector 30 mounted to the body 20to be sunk in the solution for charging the solution when the voltage isapplied thereto, a plurality of spinning nozzles 122 each of which has acapillary tube 42 for discharging the solution charged by the electricconnector 30 in a fine filament form, a filter 40 installed below theelectric connector 30, and a distribution board 50 located below thefilter 40.

The spinning nozzle pack 126 shown in FIG. 3 may be adapted not only tothe apparatus for producing nanofibers according to a preferredembodiment of the present invention, but also to an apparatus forproducing nanofibers utilizing the usual electrospinning.

The body 20 is made of engineering plastic belonging topolyetheretherketon, fluorine series or polyamide series. In the body20, the receiver 22 is prepared for receiving the solution. Slots 24 areformed on both sides of the receiver 22 in a longitudinal direction.Both ends of the electric connector 30 are inserted into the slots 24.An open end of the receiver 22 of the body 20 is combined with the cover10 in which the supplier 12 connected with the transfer line 118 isprovided. The supplier 12 transfers the solution supplied from thesupply unit 110 to the receiver 22.

The electric connector 30 is installed to sink into the solution in thebody 20. Voltages are applied to the electric connector 30 by output ofthe high-voltage unit 170, and the solution is charged by the appliedvoltage. The applied voltage and polarity are same as described above.

The electric connector 30 is made in a shape of a conductorboard or aconductor stick of a specific length along a longitudinal direction ofthe body 20, and does not have a sharp portion in order to preventconcentration of the electric field.

FIG. 4 is a front view showing a modification of the electric connectorof FIG. 3.

Referring to FIG. 4, the electric connector 30′ according to thisembodiment has valleys 34 b and ridges 34 a, which are periodicallyformed at its lower portion horizontally. In the electric connector 30′,each ridge 34 a is mounted on the body 20 to be in correspondence withthe entrance of the spinning nozzle 122, namely, the center of eachridge 34 a is fit on the center of the spinning nozzle 122.

As shown in FIG. 3, the filter 40 is located below the electricconnector 30 and inserted into the receiver 22 of the body 20. Thefilter 40 is used for removing a gelation particle and waste materialsin the charged solution.

The distribution board 50 is installed in the body 20 so as to bepositioned below the filter 40, and acts for uniformly distributing thecharged solution through each spinning nozzle 122. It is desirable thatthe distribution board 50 adopts a porous metal board or porous plasticboard having a plurality of holes of diameter from 0.5 to 3 mm.

As shown in FIG. 5, each spinning nozzle 122 includes a nozzle body 40for receiving a solution, and a capillary tube 42 positioned at lowerportion of the nozzle body 40. A screw part 44 is formed on the uppercircumferential surface of the nozzle body 40 for combining with thelower portion of the body 20.

The nozzle body 40 is made of engineering plastics having chemicalresistance including acetal, polypropylene (PP), polyethylene (PE),polyvinylidene fluoride (PVDF), fluorine series polymer such asTeflon[polytetrafluoroethylene; PTFE], polyetheretherketon (PEEK), orpolyamide series polymer such as nylon. Alternatively, the nozzle body40 may be made of corrosion resistance metal such as stainless steel(SUS).

It is preferable that the nozzle body 40 is made so that its inner wallgrows narrower downward with a streamlined gentle slope for smooth flowof the solution. It is desirable that the capillary tube 42 adopts ametal tube having an inner diameter of 0.05 to 2 mm, an outer diameterof 0.1 to 4 mm, and a length of 0.5 to 50 mm. These dimensions of thecapillary tube 42 are determined on the consideration of a thickness ofthe spun filament and an intensity of the tube. More preferably, thecapillary tube 42 has a length of 10 to 40 mm. On the other hand, alower end of the capillary tube 42 is preferably rounded for cleardischarge of the solution.

The spinning nozzle 122 shown in FIG. 5 shows that the needle-typecapillary tube 42 is fit by pressure into the lower portion of thenozzle body 40. However, a spinning nozzle 122 a according to anothermodification shows that a nozzle body 40 a and a capillary tube 42 a areintegrally made as shown in FIG. 6,

FIGS. 7 to 9 depict other embodiments of a spinning nozzle pack.

The spinning nozzle pack 126 shown in FIG. 7 includes a body 48 having aplurality of solution containers 46, and a plurality of capillary tubes41 fit by pressure into the lower portion of each solution container 46.Here, it is preferable that a distance between the body 48 and thecapillary tube 41 is substantially 3 to 80 mm for stable discharge ofthe solution.

The body 48 is preferably made of engineering plastic having chemicalresistance, which includes fluorine series polymer such as Teflon[polytetrafluoroethylene; PTFE], polyetheretherketon (PEEK), acetal, orpolyamide series polymer such as nylon.

It is preferable that the body 48 having the solution containers 46 ismade so that its inner wall grows narrower downward with a streamlinedgentle slope for smooth flow of the solution.

In a spinning nozzle pack 126 a shown in FIG. 8, capillary tubes 41 aand a body 48 a are integrally made as a whole, and the capillary tube41 a has a circular cone shape so that its diameter grows narrowertoward a lower end thereof. Here, the capillary tube 41 a has a tiltangle of 3 to 60 degree to a vertical central line, and its outercircumference grows narrower toward its lower end. Thus, it is possibleto prevent discharged solution from staining around tip of the capillarytube 41 a and concentrate the electric field on the dischargingdirection of the filament. Preferably, the tilt angle is 5 to 45degrees, and the distance between an end of a body frame 48 a and thecapillary tube 41 a is 3 to 80 mm.

As can be seen from FIG. 9, a plurality of spinning nozzles may bearranged in the spinning nozzle pack in series so that the spinningnozzle at the center portion has the longest length and others havegradually shorter lengths toward both sides on the center of thespinning nozzle located at the center portion.

In the same way, a spinning unit 126 b according to another embodimentof the present invention may be configured so that the spinning nozzlepacks 43 have gradually shorter lengths toward both ends on the centerof the spinning nozzle pack 43 located at the center portion.

Referring to FIGS. 1 and 2 again, in an apparatus 100 for producingnanofiber utilizing electrospinning according to a preferred embodimentof the present invention, the collector 130 may be grounded in order tohave electric potential difference with the voltage applied to thespinning unit 120 or applied in a negative (−) voltage.

The collector 130 is used for the purpose of piling a charged filamentdischarged from the spinning unit 120. For example, the collector 130can be moved continuously by means of a conveyor belt manner using atransfer means such as rollers 132.

On the other hand, considering that the voltage of the electricconnector 30 for charging the spun polymer filament is about 10 to 120kV, it is preferable that a distance between the lower end of thespinning nozzle 122 and the collector 130 is 10 to 100 cm. This distanceis useful for forming an appropriate electric field for stretching afilament.

The collector 130 is made of a metal board having high conductibility,or made of various kinds of conductibility materials.

FIG. 10 is a schematic view showing an apparatus for producing nanofiberaccording to another embodiment of the present invention. The componenthaving the same reference number as FIGS. 1 and 2 is identical to thecorresponding component of FIGS. 1 and 2, which has substantially thesame function.

Referring to FIG. 10, a collector 130′ is made in a shape of a rotatingdrum, differently to the embodiment shown in FIG. 1. The rotating drum130′ has a diameter of 20 to 300 cm, more preferably 30 to 200 cm, and arotating speed of 5 to 50 rpm in order to make a charged filament bepiled stably.

On the other hand, though the charged filament (P) may be directly piledon the surface of the collector 130 (see FIG. 2), the charged filament(P) is preferably coated on the surface of the piling material 182transferred by virtue of a carrier unit 180 such as rollers above thecollector 130 or 130′. The piling material 182 is nonmetallic materialsuch as textile, nonwoven fabric, film, paper, glassing paper, thinplastic sheet and glass board. The distance between the piling material182 and collector 130 or 130′ is substantially in the range of 1 to 100mm.

Referring now to FIG. 1 and FIG. 2, the control unit 140 is used for thepurpose of preventing the filament stream (S) spun from each spinningnozzle 122 from deviating its proper route due to such as repulsion anddispersion, and voltage of same polarity as the charged filament isapplied to the control unit 140. The applied voltage source to besupplied uses the output of the high voltage unit 170. However, it isalso possible to add a separate high voltage supply unit.

The control units 140 are preferably installed at least at bothlongitudinal sides of the spinning nozzle pack 126. The control unit 140is made in a shape of a conductor board or conductor stick, and controlsso that the charged filaments become repulsive and deviate from itsroute due to the same polarity.

In addition, the control unit 140 may also be installed both before themost front portion and behind the most rear portion of the spinningnozzle pack 126.

The control unit 140 may be made of acrylic board or fluorine seriespolymer such as Teflon[polytetrafluoro ethylene; (PTFE)] capable ofinducing electric charge (i.e. electric charge of same polarity ascharged filament) without voltage supply, instead of the conductionboard or conduction stick.

Considering direction and strength of the electrostatic force betweenthe control unit 140 and charged filament (P), the control unit 140 ispreferably installed near both ends of the spinning nozzle in the rangeof 1 to 20 cm from the spinning nozzle pack 126, and its lower end ispreferably set within the range of about 10 cm upward to about 20 cmdownward from the lower end of the spinning nozzle 122.

More preferably, the lower position of the control unit 140 is locatedsubstantially identical to the height of the lower end of the spinningnozzle 122, or set within the range of about 2 cm upward to about 7 cmdownward from the end of the spinning nozzle 122.

Voltages of the same polarity as the control unit 140 are applied to theinduction unit 150 shown in FIG. 1 and FIG. 2. The induction unit 150 isinstalled around the stretched charged filament stream (S) for guidingflow direction of the stream. The induction unit 150 is made in a shapeof a conduction board or a conduction stick. The induction unit 150 ischarged with the same polarity as the charged filament, thereby inducingthe filament to be piled in a restricted area of the upper surface ofthe collector 130. The induction unit 150 is preferably made of acrylicboard or fluorine series polymer such as Teflon[polytetrafluro ethylene;PTFE].

A power source equipment to supply the induction unit 150 with voltagemay adopt the high voltage unit 170 described above, or a separate highvoltage supply unit may be additionally used.

The induction unit 150 is arranged to be spaced from the chargedfilament stream discharged to the collector 130 as much as 1 to 20 cm.In addition, the induction unit 140 is positioned within the range of 1cm lower than the spinning nozzle pack 126 and 1 cm upper than thecollector 130 so as to effectively induce the filament stream to thecollector 130.

On the other hand, the height of the induction unit 150 is substantiallyin the range of 5 to 800 mm. The upper end of the induction unit 150 ispositioned in the range of 1 to 90 cm downward from the lower end of thespinning nozzle 122, and in the range of 1 to 90 upward from uppersurface of the collector 130. The induction unit 150 may be composed ofa pair of conduction boards as shown in FIG. 1. In other case, theinduction unit 150 may also be composed of two pairs of induction boards152 and 154 separated in two part as shown in FIG. 11. A porous plate156 for ensuring a space for solvent volatilization is preferablypositioned between these induction boards 152 and 154, so it is possibleto induce the stream into the piling area through two steps.

As shown in FIGS. 1 and 2, the air conditioning unit 160 is used forvolatilizing and exhausting the solvent dissolved in the chargedfilament in the space between the spinning unit 120 and the collector130, and includes solvent inspiration/exhaust means such as aninhalation fan and an exhaust fan, and a plurality of air inflow slots162.

The solvent inspiration/exhaust means may adopt various known blowers.For example, the inhalation fan is installed in the air inspirationpath, inhales dry air from outside of the apparatus, and then injectsthe dry air into the space between the spinning unit 120 and thecollector 130 through the air inflow slot 162 positioned at the upperportion of the spinning nozzle pack 126. The inhaled air volatilizes thesolvent dissolved in the charged filament (P) spun by the spinningnozzle 122, and then exhausted outside through an air exhaust path towhich the exhaust fan is installed.

The apparatus for producing nanofibers according to the presentinvention is not limited to this air circulation structure, but theinspiration or exhaust direction of the air including solvent may bechanged as desired.

Considering volatility of the solvent or an accumulation rate of thefilament, the temperature of the air injected through the solventinspiration/exhaust means (for example, the blast fan) is substantiallyset within the range of 5 to 80° C. In addition, it is also desirablethat an air velocity in the solvent exhaust path is preferably setwithin the range of 0.1 to 10 m/s in order not to affect the dischargedstream.

Hereinafter, operations of the apparatus for producing nanofibersutilizing electrospinning according to a preferred embodiment of thepresent invention will be described.

First, if fiber-forming solution stored in the supply unit 110 isconstantly supplied to the spinning unit 120 through a pump 114 and adistributor 116, the solution is charged by the electric connector 30 ofeach spinning nozzle pack 126 of the spinning unit 120. Here, theelectric connector 30 is installed to be received in the body 20 of thespinning nozzle pack 126 in order to prevent direct electrical mutualaction with the collector 130.

Next, the charged solution is discharged in a shape of fine filamenttoward the collector 130 after passing through the capillary tube 42 ofthe spinning nozzle 122. Here, the filament of nanometer diameters isstretched and spun by strong electric field formed between the collector130 and the charged filament to have a diameter of several nanometers.

In this spinning process, the control unit 140 controls the filamentstream, which tends to deviate from its route and be dispersed outward,so that the stream returns to its correct position and maintains acorrect path.

On the other hand, since the induction unit 150 is installed above thecollector 130 to surround the discharged stream, the stream tending tobe leaked out of the path is induced into the restricted piling area.

Filaments induced as described above are continuously piled on theconveyor belt or the collector 130 having a shape of a rotating drum orpiled on the upper surface of the piling material 182, and thenmanufactured into a web composed of nanofibers.

INDUSTRIAL APPLICABILITY

The apparatus for producing nanofibers according to the presentinvention gives the following effects.

First, the apparatus can stably produce a great amount of nanofiberswithout filament stream deviating from a correct path by means of thecontrol unit and/or the induction unit located at both ends of thespinning unit.

Second, in case of the spinning unit, since the electric connector forcharging the fiber-forming solution is positioned within the spinningnozzle pack, it is possible to prevent discharge stream from beingirregularly discharged, due to electrical mutual action between theelectric connector and the collector.

Third, the apparatus can prevent discharge stream from piling in acondensed state by adopting the air conditioning system for exhaustingsolvent from a great amount of discharge stream.

The apparatus for producing nanofibers according to the presentinvention can produce nanofibers having a diameter of 100 to 5000 nm byusing the electrospinning techniques, and a web having a thickness of 10to 3000 μm may be manufactured by piling the nanofibers on thecollector.

The present invention has been described in detail. However, it shouldbe understood that the detailed description and specific examples, whileindicating preferred embodiments of the invention, are given by way ofillustration only, since various changes and modifications within thespirit and scope of the invention will become apparent to those skilledin the art from this detailed description.

1. An apparatus for producing nanofiber utilizing electrospinningcomprising: a supply unit for supplying polymer materials of the liquidstate used to produce fibers; a spinning unit having a plurality ofspinning nozzles for discharging the polymer materials supplied by thesupply unit in a charged filament form; a collector installed below thespinning unit for piling the charged filament discharged by the spinningunit in a specific thickness; and a control unit charged to have avoltage of same polarity as one of the charged filament and positionedbetween the spinning unit and the collector for guiding the stream ofthe charged filament in order to prevent repulsion and dispersion of thecharged filaments discharged from each spinning nozzle.
 2. The apparatusaccording to claim 1, further comprising: an induction unit positionedbetween the control unit and the collector to surround the filamentstream for inducing the charged filament stream passing through thecontrol unit toward the collector, a voltage of same polarity as thecontrol unit being applied to the induction unit.
 3. The apparatusaccording to claim 1 or 2, further comprising a transfer mount forreciprocating the spinning unit at a predetermined speed.
 4. Theapparatus according to claim 3, further comprising an air conditioningunit for inhaling air into an air layer between the spinning unit andthe collector and discharging a solvent from the air layer to outside.5. The apparatus according to claim 4, wherein the spinning unitincludes at least one spinning nozzle pack in which the spinning nozzlesare arranged in series.
 6. The apparatus according to claim 5, whereineach spinning nozzle pack is configured so that the spinning nozzleshave gradually shorter length outward from the spinning nozzle locatedat a center portion.
 7. The apparatus according to claim 2, wherein thecontrol unit is spaced apart from the adjacent spinning nozzle as muchas about 1 to about 20 cm.
 8. The apparatus according to claim 1,wherein the collector includes a conveyor belt rotating at a speed ofabout 0.1 to 30 m/min.
 9. The apparatus according to claim 1, whereinthe collector includes a rotating drum rotating at a speed of about 5 to50 rpm.
 10. The apparatus according to claim 8 or claim 9, furthercomprising: a carrier unit for carrying a piling material to which thecharged filament is to be adhered and which is discharged to thecollector.
 11. A spinning nozzle pack for forming a polymer web byelectrostatically spinning a solution used as fiber-forming material,comprising: a body having a supplier for supplying the solution and areceiver for receiving the supplied solution; an electric connectormounted on the body to be sunk in the solution for charging the solutionwhen voltage is supplied thereto; and a plurality of spinning nozzles,each having a capillary tube for discharging the solution charged by theelectric connector in a fine filament form.
 12. The spinning nozzle packaccording claim 1, wherein the spinning nozzles are configured so thatlengths of the capillary tubes are gradually short toward both sides inthe longitudinal direction of the spinning nozzle pack from the spinningnozzle located at a center portion.
 13. The spinning nozzle packaccording claim 11 or 12, wherein the body is made of engineeringplastic belonging to polyetheretherketon, fluorine series or polyamideseries.
 14. The spinning nozzle pack according claim 11 or 12, whereinthe electric connector is made in a shape of a conductor board or aconductor stick of a predetermined length and has valleys and ridgesperiodically formed along a longitudinal direction thereof, and whereinthe ridges are fit on the center of the spinning nozzles.
 15. Thespinning nozzle pack according claim 11 or 12, further comprising: afilter installed in the receiving part for removing gelation particlesand waste materials in the charged solution.
 16. The spinning nozzlepack according claim 15, further comprising: a distribution boardinstalled in the receiving part for regularly distributing the chargedsolution passing through the filter toward each spinning nozzle.
 17. Thespinning nozzle pack according claim 11 or claim 12, wherein thespinning nozzle can be combined in an orifice of the body frameselectively.
 18. The spinning nozzle pack according claim 11 or 12,wherein the spinning nozzle is made of one selected from the groupconsisting of polypropylene, polyethylene, polyvinylidenefluoride,polytetrafluoroethylene series and polyetheretherketon, polyamideseries, or corrosion resistance metal.
 19. The spinning nozzle packaccording claim 11 or 12, wherein the capillary tube is integrallyformed with the body.
 20. The spinning nozzle pack according claim 19,wherein the capillary tube has a tilt angle of substantially 3 to 60degrees to a vertical central line so as to have a shape of a circularcone in which a diameter grows narrower toward a lower end thereof. 21.The spinning nozzle pack according claim 11 or 12, wherein eachcapillary tube substantially has an inner diameter of 0.05 to 2 mm, anouter diameter of 0.1 to 4 mm, and a length of 0.5 to 50 mm.
 22. Thespinning nozzle pack according claim 11, wherein the body is capable ofsealing up the receiving part, and includes a cover in which the supplyunit is provided.